1. Field of the Invention
This invention relates, in general, to electrostatographic copiers and printers, and more particularly, to a stapling apparatus in such a copier or printer for binding a stacked set of copy sheets.
2. Background of the Invention
Electrostatographic copiers and printers are well known. As is known, each such copier or printer can produce a series of precollated copy sheets which can then be compiled by an attached finisher portion of such printer or copier into a stacked set of sheets for binding together. As disclosed in commonly assigned U.S. Pat. No. 4,318,555 issued Mar. 9, 1982 in the name of Adamski et al, the use generally of a stapling system or apparatus to effect such binding is also well known.
Typically, such a stapling system or apparatus utilizes either preformed staples, or a continuous supply of staple material, such as staple wire, from which a desired length thereof can be cut for forming into a staple. Generally, for stapling copy sheets in copiers and printers, a stapling apparatus which utilizes a continuous supply of staple material is preferred because it can be more versatile, more economical, and more efficient than a similar apparatus which utilizes preformed staples.
However, stapling apparatus utilizing a continuous supply of stapling material ordinarily require additional mechanisms including mechanisms for metering the precise length of staple material desired for forming a staple. Such additional mechanisms are costly. For example, they may include feed wheels or feed rollers for effecting such metering as disclosed, for example, in U.S. Pat. No. 4,318,555. Unfortunately, metering mechanisms as those disclosed in the '555 patent may tend to undesirably overfeed or underfeed staple material during such metering. Additionally, such metering mechanisms also may tend, at the end of each feed cycle, to create undesirable tension in the staple material being metered, thereby resulting in frequent jams and misfeeds within the stapler unit of the apparatus.